Automatic pressure relief for tumbling barrels



July 4, 1950 H. J. EKLUND AUTOMATIC PRESSURE RELIEF FOR TUMBLING BARRELSFiled Dec. 30, 1948 Patented July 4, 1950 AUTOMATIC PRESSURE RELIEF FORTUIVIBLING BARRELS Henrik J arl Eklund, Wausau, Wis., assignor to D. J.Murray Manufacturing 00., Wausau, Wis., a corporation of WisconsinApplication December 30, 1948, Serial No. 68,161

1 Claim.

This invention relates generally to improvements in the construction andoperation of devices for relieving excessive gas pressures from theinteriors of tumbling barrels such as used for the purpose of cleaningand scouring metal and plastic articles.

The primary object of my present invention is to provide simple buteffective means for relieving the pressure created within a tumblingbarrel or the like, without necessitating interruption in the operationof the barrel or tumbling unit.

Revolvable tumbling barrels have long been utilized in variousindustries for the purpose of cleaning, scouring, deburring, burnishingand/or smoothing the surfaces and corners of various metal and plasticarticles such as small castings, stampings, and forgings; and theinteriors of these barrels are periodically loaded with batches of thearticles either alone or mixed with cleansing element, and aresubsequently sealed and revolved to cause the charges to cascade andtumble until the desired results have been accomplished. This batchloading and final dumping of the successive charges is ordinarilyeifected by means of large doors associated with the barrel peripheries,and when treating certain classes of articles such as aluminum castings,gases are created and liberated within the enclosures thus developingtremendous internal pressures which must be relieved in order to preventdisruption of the drums or barrels. In the past, such release of the gaspressures has customarily been effected by stopping the revolvingbarrels at intervals and by opening the access doors, and this periodicstoppage caused considerable annoyance and delay thus prolonging thecleaning period and reducing the output capacity of the units.

It is therefore an important object of the present invention to provideimproved instrumentalities for effecting periodic release of the gaspressures thus created in a tumbling barrel, while the unit remains inoperation.

Another important object of this invention is to provide an automaticpressure relief for tumbling barrels or the like, which is dependable inoperation and may be readily applied to either existing or new units atmoderate cost.

A further object of the invention is to provide an improved tumblingbarrel internal pressure r lief device which functions to effectivelyrelease the gas pressure without permitting undesirable escape of solidsand dust, and which also requires minimum attention.

Still another object of my invention is to provide an improved pressurerelief valve for revolve5 ing barrels or drums loaded with cascadingsolid materials, which is durable in construction, easily applicable totumbling barrels, while also being reliable and efficient in operation.

These and other objects and advantages of the invention will be apparentfrom the following detailed description.

A clear conception of the improved apparatus and of a typical tumblingbarrel embodiment of my invention may be had by referring to the drawingaccompanying and forming a part of this specification wherein likereference characters designate the same or similar parts in the variousviews. 1

Fig. l is a somewhat diagrammatic front elevation of a tumbling barrelinstallation showing the mode of installing or applying the improvedpressure relief valves;

Fig. 2 is a similarly diagrammatic end view of the tumbling barrelinstallation shown in Fig. 1;

Fig. 3 is an enlarged top view of one of the pressure relief valves andof the cam element for automatically actuating the same;

Fig. 4 is a similarly enlarged central section through the valve unit,showing the same associated with a fragment of a tumbling barrel andopened by coaction with its actuating cam; and

Fig. 5 is a likewise enlarged part sectional side elevation of the valveunit provided with an antifriction valve actuator.

While the invention has been illustrated as having been applied to atwo-compartment Octagonal tumbling barrel wherein each compartment isprovided with only one automatic pressure relief valve, it is not mydesire or intention to unnecessarily restrict the applicability of theimprovement by virtue of this limited embodiment; and it is alsocontemplated that specific descriptive terms used herein be given thebroadest possible interpretation consistent with the disclosure.

Referring to the drawing, the typical tumbling barrel installation shownin Figs. 1 and 2 by way of illustration, comprises in general anoctagonal drum or barrel 1 the interior of which is divided by apartition 8 into two compartments 9, lil each of which is normallysealed by a removable peripheral access door ll clamped in place by wingnuts I2, the barrel 1 being provided with opposite horizontally alinedend shafts l4 coacting with bearings l5 mounted upon fixed supports l6and one of which shafts I4 is adapted to be driven by gearing ll so asto constantly rotate the shafts and drum during normal operation of themill. All of this structure is well known to those familiar with theart, and the doors I l are in order to avoid excessive wear.

adapted to be readily removed while the barrel 1 is at rest, in order topermit the chambers or compartments 9, If] to be conveniently loadedwith fresh batches of articles to be treated, and to effect rapidunloading by gravity of the finally treated charges.

When certain types of articles such as aluminum castings are to betreated, gases are generated within the chambers 9, I and tend to createtremendous pressures therein which must be liberated before they damagethe drumt'l; andin order to effect such timely release of: these gases,I provide one or more relief valves I8 such I as shOWn in Figs. 3 and 4,for each ofthe come partments 9, If]. consists primarily of a housing orcasing I9 having a valve seat 29 formed therein and:in.com

munication at one side with the adjacent drum compartment 9, I0 througha valve supporting nipple 2|, and at its opposite side with the ambientatmosphere through a gas escape opening 22; and avalve body or disk 24constantly urged toward the seat 20 by a compression spring 25 andhaving an actuating stem 2%; piercing the casing I9 and provided at itsouter-end'with a valve opening button 21 which is-periodicallyengageable with an operating cam 28- fixedly secured to a stationarymounting bracket 29 carried by the adjacent barrel support Iii.

The valve casing I9 may be permanently attached to the outer endof thesupporting nipple 2| in any suitable manner, and the innerend of thisnipple 21 is preferably detachably secured to the periphery of thebarrel 1 by means of a reinforcing plate 3| and is spanned by a'relativelyfine screen 32 firmly held between a rubber gasket 33 and aclamping washer 34. This screen 32 prevents solid material from escapingfrom the adjacent vented chamber 9, I0, and may be quickly cleaned ifclogged by merely" removing the valve I8'and its attaching nipple. Thevalve housing I9 may also be providedwith aremovable cap 35 againstwhich the valve closing spring 25.. reacts, and the valve disk 24 has areplaceable seating. washer 35 adaptedto directly'engage the valve seat20.

The valve stem 26 upon which. the disk 24 is mounted, is guided forreciprocation within the closure cap 35 and in a stuffing boirt's'associated I with the casing I9 remote from the cap 35;

and the valve opening button 2'! may be firmly but detachably secured tothe outer extremity of the stem ZB inany suitable manner so as to permitinsertion or removal of the disk 24, spring 2.5,.and stem 26 relativetothe casing I9 when the cap 35 hasbeen removed. As shown in Fig. 5,. ananti-friction valve actuating ball 39 coactingv with the stem 26 andwith the cam 23, and which is held in place by a sleeve 40 and retainerv II, may be substituted for the button 21, The" buttons 27 or balls 39are periodically engageable with the adjacent stationary, cams. 28.whenever the barrel! to which the valves I8 aresecured, is

being revolved; and severalof these valves I8 may be associated with.each. end of the. revolving drum-if itbecomesdesirable tovent' theadjacent chambers 9,.I0.-mor.e than-once during each completerevolution.of.. the barrel In some cases it may also be. desirable toomit the partition 8 thereby providing onlya single compartment withinthe barrel.'l', and' the valves" I8 at the opposite ends of the drum.may then be'staggered so asto. produce successive opening there- Eachof these relief valves'lli' While the normal operation of the improvedautomatically vented tumbling barrel assemblage should be apparent fromthe foregoing description, a short rsum will be given. The barrelcompartments 9, Il] may be loaded with batches of the articles to betumbled, upon opening of the doors I I, and after sufficient loading hasbeen effected and the doors have been sealed, the barrel I may beconstantly revolved by application of driving power to the gearing I! soas to cause the charges to cascade within the confining chambers. Thisrevolution of the barrel 1 causes the valves I8 to simultaneouslyrevolve about the drum axis, and as the actuating balls 39 or buttons 27of the vent valves approach and periodically engage the adjacent fixedcams 28 as in Fig. 3; they ride along the cam surfaces and. unseatthevalve disks 24 while compressing the adjoining springs 25 as in Fig.4. The pressures from within the compartments 9, ID will then bereleasedto the ambient atmosphere through the openings 22, and as thevalves is advance beyond the'cams 2B the springs 25 quickly becomeeifective to close the valve disks 24 against the seats 205 The severalvent valves I8 are thus periodically and automatically opened and closedby the fixed camsZS/during normal'operation of the mill and whenever thegas discharge nipples 2| reach the highest points of their paths oftravel, thereby insuring free escape of the gases and release of thepressure. The valves I8 may be removed from time to time for inspectionand'cleansing of the screens 32, but these screens may also be readilycleaned without removing the valves by delivering a jet of compressedair reversely through the valve casing I9 when the barrel 1 is beingloaded or unloaded and the doors i! are open. The successive automaticopening and closing of the valves It will continue as long as thetumbling unit is in operation, and the chambers 9', ID will therefore beeffectively vented so that the establishment of excessive pressurestherein will be avoided at all times.

From the foregoing detailed description, it will be apparent that mypresent invention in fact provides simple and efiective means forventing the chambers or compartments of a revolving tumbling barrelmill, without interrupting the normal operation thereof. The release ofthe internal pressure is effected automatically and periodically Withoutattention on the part of the operator, and does not require manualopening of doors or slides. By locating the relief valves I8 so thatthey will open atthe highest point of travel, most effective release ofthe gas pressure is assured, andthe improved valves I8 may be readilyassembled or dismantled, as well as being conveniently applicable toeither existing or new barrels I. As previously indicated, any desirednumber of the improved valves may be applied to single or multiplecompartment drums or barrels I of various types and sizes, and thevalves l8 and earns 26 do not in any manner interfere with the normalfunctioning of the mills to which they are applied. The invention hasgone into highly successful actual use, and has proven satisfactory inevery detail.

It should be understood that it is not desired to limit this inventionto the exact details of construction or to the precise mode of use ofthe pressure relief assemblage herein shown and described, for variousmodifications within the scope of the appended clai-m may occur topersons skilled in the art.

I claim:

A gas relief device for a revolvable tumbling barrel rotatable about ahorizontal axis ,and containing a mass of cascading articles adapted toshed fine particles, said device comprising, a rigid nipple secured toand radiating from the outer periphery of an end 01. the barrel, a finescreen interposed between the inner end of said nipple and the interiorof the barrelg'a poppet valve having a casing secured to andcommunicatinglwith the outer end of said nipple and also communicatingwith the ambient atmosphere, said valve being provided with a springpressed valve disk opening outwardly away from the barrel interior andmounted upon a stem horizontally slidably coacting with the casing onopposite sides of the disk and projecting outwardly beyond the adjacentend of the barrel, a stationary cam mounted above and outwardly beyondsaid barrel end in the path of revolution of the outer end of said valvestem, and a rounded contact element interposed between said outer stemend and said cam and having a curved coritact surface graduallyengageable with said ca'm.

whenever said valve reaches its highest point. of travel.

I-IENRIK JARL EKLUND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

